Multi fuel co-injection system for internal combustion and turbine engines

ABSTRACT

An improved multi-fuel supply and co-injection system and method for powering internal combustion and turbine engines, whereby various combinations of fuels, both liquid and gaseous, may be mixed together and fed into the system, under the real-time control of a microprocessor responding to a variety of sensors and acting on a variety of control devices, all working together in a manner designed to enhance the utilization of the thermal content of the various fuels, and in particular to enhance the combustion efficiency and increase the power output while decreasing the consumption of fuel, calculated both by quantity and by cost and whereby the liquid fuel lubricates the moving parts of the injection system.

RELATED APPLICATIONS

This application claims priority to and is entitled to the filing dateof U.S. Provisional application Ser. No. 60/739,594 filed Nov. 26, 2005,and entitled “Gaseous Enhanced Fuel System for Combustion Engines”. Thecontent of the aforementioned application is incorporated herein byreference.

INCORPORATION BY REFERENCE

Applicant hereby incorporates herein by reference any and all U.S.patents and U.S. patent applications cited or referred to in thisapplication.

TECHNICAL FIELD

Aspects of this invention relate generally to fuel injection systems,and more particularly to an apparatus and method for multi-fuelco-injection systems for internal combustion and turbine engines.

BACKGROUND ART

The following art defines the present state of this field:

Great Britain Patent Application Publication No. GB2413824 to Bysveen,et al. describes a diesel-cycle internal combustion engine whichoperates using a liquified hydrocarbon gas fuel containing an ignitionimprover, eg a cetane improver. The gas may be supplied to thecombustion chambers using a common rail fuel supply system. The fuel andmethod of operating the diesel-cycle engine can be used in a range ofapplications such as, for example, road or marine vehicles or in staticapplications such as electrical generators. The fuel and the ignitionimprover may both be supplied to the engine in liquid form eitherpre-mixed in bulk (FIG. 1); kept in separate tanks 202, 204, pressurisedby separate pumps 207, 208 and mixed in the injector 206; or mixedbefore reaching a common rail (301, FIG. 3A) or within a common rail(305, FIG. 3B). Alternatively, eg with methane or natural gas, the fuelmay be pressurised rather than liquefied and the ignition improver issuspended as a mist in the gas. The fuel may be eg methane, ethane,propane, butane or natural gas. The ignition improver may be dieselfuel, any mixture of alkanes and alkenes, a mono-ether, a di-ether, DME(diethyl ether), GTL (Gas-to-Liquid), alkyl and/or aryl nitrates.

U.S. Pat. No. 7,040,281 to Crawford, et al. describes a method ofoperating a gaseous-fueled internal combustion engine comprisesselecting one of at least two predetermined operating modes as afunction of engine load and engine speed. A first operating mode isselected when said engine is commanded to operate within a first regioncorresponding to a low load and low speed range, and a second operatingmode is selected when said engine is commanded to operate within asecond region distinct from said first region and corresponding to atleast one of a greater load and a greater speed range compared to saidfirst region. In the first operating mode, the gaseous fuel isintroduced in a single injection event with the injection valvecommanded to open with a constant amplitude A1. In the second operatingmode, the gaseous fuel is introduced in a single injection event and theinjection valve is commanded to begin with a constant amplitude A2 for apredetermined time and then to open to an amplitude A3, whereinamplitude A3 is greater than amplitude A2.

U.S. Pat. No. 7,019,626 to Funk describes systems, methods andapparatus' of converting an engine into a multi-fuel engine areprovided. One embodiment reduces particulate emissions and reduces theamount of combusted gasoline or diesel fuel by replacing some of thefuel with a second fuel, such as natural gas, propane, or hydrogen. Onefeature of the present invention includes a control unit for meteringthe second fuel. Another feature of the present invention includes anindicator that indicates how much second fuel is being combustedrelative to the diesel or gasoline. This Abstract is provided for thesole purpose of complying with the Abstract requirement rules that allowa reader to quickly ascertain the subject matter of the disclosurecontained herein. This Abstract is submitted with the explicitunderstanding that it will not be used to interpret or to limit thescope or the meaning of the claims.

Japanese Patent Application Publication No. EP1211407 to Watanabe, etal. describes injectors 2 are connected to a common rail 4 viarespective dispensing conduits 3. A mixture of a liquid fuel fed from aliquid fuel tank 2 and an additional fluid fed from an additional fluidtank 9 is formed, and is fed to the common rail 4. The additional fluidcontained in the mixture is turned to its supercritical state, and themixture is injected from the injectors 2 to the engine. The inlets ofthe dispensing conduits 3 are positioned, with respect to the commonrail 4, to open out into a liquid fuel layer which will be formed in thecommon rail 4 when a separation of the mixture occurs.

German Patent Application Publication No. DE19609799 to Danckert, et al.describes an engine can be fed selectively with a first fuel or with asecond fuel in the form of clean fuel or an emulsion of fuel and afurther material insoluble in relation to the fuel. The fuel is fed in acircuit through the common pre-accumulator (6). The fuel injectionequipments (1) have a through passage for the fuel fed from the commonpre-accumulator. The part of the fuel not injected from the injectionnozzles into the engine is fed back via a return flow conduit (8) to thecommon pre-accumulator.

U.S. Pat. No. 5,125,367 to Ulrich, et al. describes a method andapparatus for producing a water-in-fuel-emulsion and emulsifier-freewater-in-fuel-emulsion. The apparatus for generating a fuel wateremulsion for the operation of an injection pump, particularly that of adiesel motor, comprising a rotationally symmetric vortex chamber (1)with a tangential inlet and a tapering axial outlet. In order togenerate a fine homogeneous emulsion in colloidal state, having a sizeof the suspended water droplets of 1000 nm or less, the axial endportion of the vortex chamber (1) facing away from the outlet issurrounded by a ring channel (7) running coaxially to the vortex chamber(1), the ring channel (7) being connected to the vortex chamber (1) viainlet slots (9) which are tangentially aligned to it and in which a fuelinlet channel (8) tangentially ends. An electromagnetically controlledwater injection nozzle (10) leads into the end portion of the vortexchamber (1) at the inlet side thereof. The outlet (2) of the vortexchamber (1) opens via an enlargement (3) into a suction chamber (4) of aradial wheel (5) which is arranged in a pump chamber (12) having anoutlet channel (13) in the area of the circumference of the radial wheel(5) to which a forward conduit leading to the injection pump and arecirculation conduit leading to an emulsion inlet channel (15) areconnectable which also ends tangentially into the ring channel (7). Anintake channel (16), to which a return conduit coming from the injectionpump is connectable, leads into the suction chamber (4) of the radialwheel (5).

U.S. Pat. No. 6,866,756 to Klein describes an electrolyzer forelectrolyzing water into a gaseous mixture comprising hydrogen gas andoxygen gas. The electrolyzer is adapted to deliver this gaseous mixtureto the fuel system of an internal combustion engine. The electrolyzer ofthe present invention comprises one or more supplemental electrode atleast partially immersed in an aqueous electrolyte solution interposedbetween two principle electrodes. The gaseous mixture is generated byapplying an electrical potential between the two principal electrodes.The electrolyzer farther includes a gas reservoir region for collectingthe generated gaseous mixture. The present invention further discloses amethod of utilizing the electrolyzer in conjunction with the fuel systemof an internal combustion engine to improve the efficiency of saidinternal combustion engine.

U.S. patent application Publication Ser. No. 10/277,841 to Kleindescribes an arrangement and method is disclosed for improving the fueleconomy of an internal combustion engine of the type having a carburetorfor mixing a fuel with air, in which the air is saturated with a mixtureof ether, alcohol and water.

U.S. Pat. No. 4,412,512 to Cotten describes a fuel supply system isdisclosed in which oil and water are mixed and delivered under pressureto a nozzle or other atomizing means at which combustion is to occur.The mixture of oil and water is delivered to the atomizing means alongconduit means and those conduit means include means to produce agitationof the oil and water so that an intimate mixture of oil and water isdelivered to the atomizing means. Complete emulsification occurs at theatomizing means to promote combustion.

More generally, in the prior art, typically a single fuel is held in atank and fed into the engine through a carburetor or injection system.In a carburetor system liquid fuel is mixed with the air in thecarburetor, and the fuel-air mixture is admitted to the combustionchambers through an intake manifold and compressed in the combustionchamber. In an injector system the air is fed into the combustionchambers and the fuel or fuels injected directly into the combustionchamber and mixed with the compressed air. Various embodiments have beenrun on gasoline, diesel, kerosene, propane, hydrogen, natural gas,generated methane, or other flammable substances. In some embodiments agaseous enhancement, such as hydrogen, water vapor or nitrous oxide isadded to the air inflow stream to increase the power extracted from theliquid fuel. Some engines are modified to run entirely on a gaseous fuelinstead of a liquid fuel.

DISCLOSURE OF INVENTION

Aspects of the present invention generally relate to an improvedmulti-fuel supply and co-injection system for powering internalcombustion and turbine engines, whereby various combinations of fuels,both liquid and gaseous, may be mixed together and fed into the system,under the real-time control of a microprocessor responding to a varietyof sensors and acting on a variety of control devices, all workingtogether in a manner designed to enhance the utilization of the thermalcontent of the various fuels, and in particular to enhance thecombustion efficiency and increase the power output while decreasing theconsumption of fuel, calculated both by quantity and by cost. Oneconsideration in the configuration of the system is that the thermalresponse of some types of fuel may be significantly enhanced by thepresence of other fuels consisting of a different chemical composition.For example, the combustion characteristics of vegetable oil may beconsiderably enhanced by the presence of an excess of hydrogen over thatcontained within the vegetable oil itself, and additional oxygen fedinto the system may be expected to enhance the combustioncharacteristics of all the fuels involved.

Accordingly, further aspects of the invention generally relate tosystems and methods of introducing combustible materials into thecombustion chambers of an internal combustion or turbine engine toproduce power by burning of the fuel mixed with air under pressure. Thepurpose of the present invention is to provide for a system whereby avariety of fuels, both gaseous and liquid, may be mixed together and thecombination introduced into the engine under pressure in a manner andproportion that enhances the total burn reaction above what could beobtained from any of the single fuels in isolation and that makespossible the use of less expensive fuel sources without impeding thefunction of the engine or reducing the power which it can produce.

Another feature of the invention is to use the first fuel such asdiesel, vegetable oil or motor oil etc. to act as a lubricatingcomponent for the moving parts in the injection system.

In still further aspects of the invention, for one example, usedvegetable oil may be mixed with gaseous hydrogen and injected into thecombustion chambers under high pressure to produce a combustionequivalent to premium diesel fuel at a fraction of the cost. In anotherexample, propane may be reduced to a liquid under pressure and mixedwith petroleum diesel fuel in a proportion that maximizes the combustioncharacteristics of both and results in substantially increased fueleconomy. In a more complex embodiment several different types of fuelmay be tanked separately and metered into the system at varying rates inorder to meet the changing demands of the engine for power and torqueunder varying loads and speeds in the most efficient manner.

Other features and advantages of aspects of the present invention willbecome apparent from the following more detailed description, taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, the principles of aspects of the invention.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings illustrate aspects of the present invention.In such drawings:

FIG. 1 is a schematic view of an exemplary embodiment of the presentinvention such as might be used in a large stationary installation witha variety of different fuels available from time to time;

FIG. 2 is a partial schematic view of an alternative exemplaryembodiment such as might be installed in a vehicle for co-injecting twofuels;

FIG. 3 is a partial schematic view of an exemplary accumulator locatedin the fuel circulation system of FIG. 1;

FIG. 4 is a schematic view of an alternative exemplary embodiment of theinvention including such as may be used in a variety of installations;and

FIG. 5 is a partial schematic view of an exemplary hydrogen generatingsystem located in the fuel supply system of FIG. 4.

MODES FOR CARRYING OUT THE INVENTION

The above described drawing figures illustrate aspects of the inventionin at least one of its exemplary embodiments, which are further definedin detail in the following modes.

The system is generally comprised of a multiplicity of tanks containinga variety of types of fuel which are delivered to the combustionchambers of the engine by means of various sensors, pumps, and controldevices so constructed and arranged as to combine the different fuels atcarefully metered rates into a circulating homogenizing commonstream—all under the control of a microprocessor and computer.

When the system is in operation, a throttle mechanism responds directlyto an action by the operator by increasing the amount of the pre-mixedfuel from a fuel circulation system into a common rail injector systemor other device designed to introduce fuel into the engine's combustionchambers. Some of this pre-mixed fuel is contained within an accumulatorin the fuel circulation system and is held under pressure ready forinstant use. Sensors monitor the pressure of the fuel in the accumulatorand forward the data to the microprocessor, which activates the variouspumps and control valves to maintain the supply of fuel in thecirculation system at optimum level with the appropriate mix of thevarious fuel types. The relative balance of fuel types in the fuelmixture may be adjusted during the operation of the engine to compensatefor different operating requirements. For example, an engine operatingat reduced torque in a steady rpm configuration, such as driving anelectrical generator under reduced load, may operate more efficientlywith a fuel mix different from that required for rapid accelerationunder heavy torque requirements or during startup in a low-temperatureenvironment. Various fuel mix requirements can be programmed into thecomputer and stored in the computer's non-volatile memory in order tomaintain the desired configuration when the engine is turned off. In apreferred embodiment the programming of the computer is accomplishedtransparently by simple operator adjustments on the engine controlpanel, so that the operator has no need to even know that a computer isoperating the system. Rather, the computer's program may be modified inreal time by the machine itself, based on transient power demands and onthe movement and positions of dials and switches on the engine controlpanel, which are similar in all essential respects to the controls anoperator may be accustomed to in other machine environments.

In one exemplary embodiment, the engine will be of a “diesel” type setup to run on diesel fuel and/or vegetable oil, separately or incombination, along with one or more gaseous fuels such as propane and/orhydrogen. In such an embodiment the hydrogen may be either supplied fromhigh-compression tanks or generated on-site while the engine is running.A possible configuration of such an embodiment could include: a tank tocontain the petroleum diesel fuel; a tank to contain the vegetable oilor other bio-diesel fuel, each with an associated fuel pump to feed thefuel into the system at an appropriate rate and pressure; a tank tocontain the propane fuel; a tank or other system to contain or generategaseous hydrogen or a hydrogen/oxygen mix; a pressure regulator toregulate the outflow from the propane tank; a sensor to read thetemperature of the gaseous propane as it flows from the propane tank; aflow-control valve with associated flow sensor to control the amount ofpropane entering the system; a positive displacement pump to raise thepressure of the gaseous propane to a level at which the propane returnsto liquid form ready to be introduced into the fuel mix at a controlledrate, a fuel circulation conduit; a circulation pump to keep the fuelmixture in a homogenous state while awaiting transfer into the injectionpump plungers for injection into the combustion chambers; an accumulatorto hold and stabilize excess surges of fuel; a microprocessor controlsystem, including non-volatile memory, programmed to read all of thesensors and to respond appropriately with control signals to all of theactive component parts, including the pumps and control valves; andtubing, hoses and fittings to contain and direct the various types andmixtures of fuel. It is assumed that in such a configuration the fuelmixture may be fed into a common rail injector system, in which aninjector pump, as commonly used in the prior art, will provide the highpressure to inject the fuel mixture into the combustion chambers.

Other exemplary embodiments may simplify the above arrangement byomitting one or more fuel tanks and various sensors, valves and pumps.In such an alternative embodiment, the pressure of the propane orhydrogen, as set by the regulator at the tank may be used to control theamount and rate of flow of the liquid fuel.

The hydrogen may be supplied from a high pressure reserve tank or begenerated on-site by electrolysis of a water solution or by other meansnow known or later developed. If the hydrogen is generated on-site froma water solution, the oxygen component may be injected together with thehydrogen into the fuel mix or directed separately into the intakeairflow.

Persons skilled in the art will recognize various possibilities forcombining different components as described herein to meet the differingrequirements of particular situations, whether stationary or in movingvehicles.

The multi-fuel co-injection system and method of the present inventionis generally designed to improve the power of various engines, turbinesand the like, which power may be extracted from a variety of differentfuel types now known or later developed. Depending on the particularchemical composition of a type of fuel, the combination with anotherfuel type may substantially improve the combustion characteristics sothat the two fuels mixed together generate power more efficiently thanthe fuels burned separately. Thus, the system may substantially reducethe operating costs by enhancing the burn characteristics of a lessexpensive fuel through addition of a small proportion of a moreexpensive fuel having a different chemical composition or combustioncharacteristic.

As will be appreciated by those skilled in the art, a system accordingto the present invention may be constructed with various degrees ofcomplexity depending on the particular use to which the power system isto be applied. In general, the more complex the system, the greaterefficiencies may be achieved. However, some situations, such asinstallation in a motor vehicle, may require considerablesimplification. Appropriate design of such a simplified system asdisclosed herein still provides considerable advantages in efficiency offuel consumption over the prior art.

In order to achieve still further operating efficiency, a relativelymore complex embodiment such as that shown in FIG. 1 may be employed.This system may be a diesel type internal combustion engine with amulti-fuel supply which consists in part of a tank 10 containingpetroleum diesel fuel, a tank 11 containing a bio-diesel fuel such asvegetable oil, a tank 12 containing propane, and a tank or other supplysource 13 providing hydrogen either from a compressed tank or from ahydrox generator as described further below.

A low-pressure fuel pump 14 is connected to tank 10 by means of a tube15. Another tube 16 connects pump 14 to a combination pressure/flowsensor and control valve 17, which interacts by means of an electricalconnection 18 with a micro-processor control unit 19, which receivesdata from the sensor 17 and returns a control signal to determine theamount and rate of fuel flowing in tube 56 to the manifold 20 where itis combined with the bio diesel fuel from tank 11.

A second tank 11 may contain bio-diesel or vegetable oil or other liquidfuel now known or later developed. A low-pressure pump 21 is connectedto tank 11 by means of a tube 22. Another tube 23 connects to acombination pressure/flow sensor and control valve 24, which interactsby means of an electrical connection 25 with the micro-processor controlunit 19 which receives data from the sensor 24 and returns a controlsignal to determine the amount and rate of fuel to be flowing in tube 57to the manifold 20 where the bio-fuel is combined with the fuel from theother sources.

A third tank 12 may contain propane, or other gaseous fuel such asnatural gas or generated methane. A tube 26 connects the tank 12 to apressure regulator 27 and controls the pressure of the gaseous fuelreleased from tank 12 into the low-pressure part of the system. A tube28 connects the pressure regulator to a combination sensor and controlvalve 29 which interacts by means of an electrical connection 30 to themicroprocessor control unit 19, which receives data from the sensor 29and returns a control signal to determine the amount and rate of gaseousfuel to be forwarded to an optional positive displacement pump 31 thatraises the pressure of the gaseous fuel to a level appropriate to permitpositive mixing with the liquid fuel. A further combination sensor andcontrol valve 32 interacts with the microprocessor control unit 19 inthe manner already described and forwards the re-pressurized gaseousfuel to the manifold 20 via tube 33 where the gaseous fuel is combinedwith the fuel from the other sources in the system.

A fourth tank 13 may contain hydrogen under high pressure. A tube 34connects the tank 13 to a pressure regulator 35 and controls thepressure of the hydrogen released from tank 13 into the low-pressurepart of the system. A tube 36 connects the pressure regulator 35 to acombination sensor and control valve 37 which interacts by means of anelectrical connection 38 to the microprocessor control unit 19, whichreceives data from the sensor 37 and returns a control signal in themanner already described to forward the hydrogen by means of tube 58 toa positive displacement pump 39, where the pressure of the hydrogen israised to a level appropriate to mix well with the fuel from othersources in the system. Another combination sensor and control valve 40interacts with the microprocessor control unit 19 via an electricalcontact 41 in the manner already described, from where there-pressurized hydrogen is conducted by means of tube 42 to the manifold20 where it is combined with the fuel from the other sources in thesystem.

In an alternative embodiment, tank 13 may be replaced by a hydrogengenerator as shown and described in connection with FIG. 4. In such acase the pressure regulator 35 and the combination sensor and controlvalve 37 would be omitted and the hydrogen, as generated in thegenerator 13 represented in FIG. 4, would flow in tube 34 directly tothe positive displacement pump 39 to be mixed into the system asdescribed above.

While exemplary components are shown and described as including one ormore tanks, pumps, control valves, sensors, and the like, those skilledin the art will appreciate that the use of such components, alone or inany combination, is merely illustrative and that the invention is not solimited. Rather, any such components now known or later developed forthe purpose of storing, transferring, controlling and measuring ormonitoring one or more fuels within such a fuel delivery system arepossible without departing from the spirit and scope of the invention.

With continued reference to FIG. 1, after the fuels from the varioussources are combined in the manifold 20, the mixture is conducted bymeans of tube 43 to a high pressure positive displacement pump 44 wherethe pressure of the fuel is brought up to a level appropriate for theparticular fuel mix. The pressure in the circulation loop is sensed andregulated by the high pressure combination flow sensor and control valve45 in interaction via the electrical connection 46 with themicro-processor control unit 19 in the manner as already described. Thehigh pressure fuel mixture is then circulated in the fuel circulationline 47 by action of a circulation pump 48, the pressure of which isregulated by the high pressure positive displacement pump 44 so that thefuel mixture is not allowed to separate into its component parts. Anaccumulator 49, as more fully described below in connection with FIG. 3,acts as a reserve supply and pressure holding reservoir to provideinstantaneous fuel reserves in case of a surge in fuel requirementsresulting from a sudden power demand. A feedback line 50 is provided forblow by of fuel to be returned from the accumulator 49 back to the lowside of the high pressure positive displacement pump 44 for re-mixinginto the circulating fuel supply.

The injector pump 51 is fed fuel from the circulation loop 47 asrequired for the engine's operation and injects the fuel mix into thecombustion chambers 52 at high pressure through the injectors 55 in themanner as is well known in the art.

Additional tanks, containing other types of fuel, may be added to thissystem and controlled in a manner essentially as described above.

Turning now to FIG. 2, there is shown an alternative exemplaryembodiment of the fuel delivery system of the present invention that isrelatively simplified such as might be appropriate for installation in amotor vehicle. This system may be of a diesel type internal combustionengine as installed, for example, in a motor vehicle, with a multi-fuelsupply that consists in part of a tank 10 containing petroleum dieselfuel or vegetable oil or other bio-diesel fuel and a tank 11 containingpropane or some other gaseous fuel. In some embodiments this alternatefuel may be hydrogen from a high pressure supply tank or from a hydrogengenerator, such as described in connection with FIG. 4.

A low-pressure fuel pump 14 is connected to tank 10 by means of a tube15. The output of this pump 14 is controlled by the microprocessorcontrol unit 19 by means of an electrical connection 25 in response tosignals received by the microprocessor control unit 19 from other partsof the system as described below. A tube 56 conducts the liquid fuel tothe manifold 20 at a pressure established by the low pressure pump 14under the control of the microprocessor control unit 19.

A pressure regulator 21 is connected to tank 11 by means of tube 22. Theflow and pressure of the gaseous fuel is controlled by the pressureregulator 21 in response to signals from the microprocessor control unit19, according to data received and processed from other parts of thesystem.

The liquid and gaseous fuels flow to the manifold 20 at rates andpressures, controlled by the microprocessor control unit 19, appropriatefor effective mixing based on the properties of the respective fuels.The pressure of the gaseous fuel as it flows to the manifold 20 providesan effective control factor for the amount of liquid fuel entering thesystem.

The remainder of the simplified system with components related to thehigh pressure positive displacement pump and the fuel circulation lineare essentially similar to the description given in reference to FIG. 1.

Referring now to FIG. 3, there is illustrated an exemplary accumulator49 as attached to the fuel circulation line 47 shown in FIG. 1 andproviding for return of fuel blow by via feedback line 50 to the lowside of the high pressure positive displacement pump 44 for re-mixinginto the circulating fuel supply as also shown in FIG. 1. Theaccumulator 49 thus generally consists of a cylinder closed at bothends, a connector 59 connecting the high pressure side of theaccumulator to the high pressure fuel circulation line 47, and anothertube 50 connecting the low pressure side of the accumulator to the tube43 and the low pressure side of the high pressure positive displacementpump 44. A sealed piston 60 separates the high pressure and low pressuresides of the accumulator 49. A spring 61 in the low pressure side of theaccumulator presses against the piston 60 and sustains the pistonagainst the pressure exerted by the fuel circulation line 47. The blowby hose 50 conducts fuel back to the low pressure side of the highpressure positive displacement pump 44.

Turning to FIG. 5, there is shown a partial schematic view of thehydrogen generator generally denoted 13 in FIG. 4, which may provide asource of hydrogen to the system other than by a high pressure hydrogensupply tank. A grid 53 consisting of two or more screens or perforatedplates insulated from each other and connected alternately to positiveand negative poles of a DC current supply 67 is immersed in an aqueoussolution 62 in the tank 13 which is closed at the top with provision fortransport means 63 for the oxygen and hydrogen produced by electrolysis.In such an exemplary embodiment the oxygen and hydrogen from theelectrolysis may be directed into the positive displacement pump 39 tobe further processed as described in FIG. 4

While aspects of the invention have been described with reference to atleast one exemplary embodiment, it is to be clearly understood by thoseskilled in the art that the invention is not limited thereto. Rather,the scope of the invention is to be interpreted only in conjunction withthe appended claims and it is made clear, here, that the inventorbelieves that the claimed subject matter is the invention.

What is claimed is:
 1. A system for multi-fuel injection within anengine from at least two fuel supplies, the engine having an injectorincluding an injector pump, the improvement comprising: a manifold influid communication with and downstream of the at least two fuelsupplies wherein fuels from the at least two fuel supplies are mixed toproduce a fuel mixture as controlled by a combination flow sensor and acontrol valve located in-line between each fuel supply and the manifold;and a high-pressure positive displacement pump in fluid communicationwith and downstream of the manifold and in-line between the manifold andthe engine, whereby the fuel mixture is brought to higher pressurebefore being injected by the injector; wherein: a first fuel is in aliquid state as supplied by a first fuel supply and delivered to themanifold; and a second fuel is in a gaseous state as supplied by asecond fuel supply and delivered to the manifold, whereby the fuelmixture is a liquid-gaseous fuel mixture and the positive displacementpump pressurizes the liquid-gaseous fuel mixture prior to injection. 2.A system for multi-fuel injection within an engine from at least twofuel supplies, the engine having an injector including an injector pump,the improvement comprising: a manifold in fluid communication with anddownstream of the at least two fuel supplies wherein fuels from the atleast two fuel supplies are mixed to produce a fuel mixture ascontrolled by a combination flow sensor and a control valve locatedin-line between each fuel supply and the manifold; and a high-pressurepositive displacement pump in fluid communication with and downstream ofthe manifold and in-line between the manifold and the engine, wherebythe fuel mixture is brought to higher pressure before being injected bythe injector, the improvement further comprising a circulation loopconnected between the positive displacement pump and the injector pumpof the engine, the circulation loop including a circulation line and acirculation pump substantially constantly circulating the fuel mixtureand delivering the fuel mixture to an inlet of the injector pump.
 3. Thesystem of claim 2, wherein the circulation loop further includes anaccumulator within the circulation line, whereby pressure and fuelrequirement surges are substantially absorbed by the accumulator.
 4. Thesystem of claim 3, wherein the circulation loop further includes afeedback line leading from a side of the accumulator substantiallyopposite the circulation line back to the inlet of thepositive-displacement pump, whereby blow by fuel mixture is reclaimedand returned to the inlet of the positive displacement pump for furtherprocessing.
 5. A system for multi-fuel injection within an engine fromat least two fuel supplies from which a fuel mixture is prepared, theengine having an injector including an injector pump, the improvementcomprising: a circulation loop in fluid communication with the at leasttwo fuel supplies and including a circulation line and a circulationpump substantially constantly circulating the fuel mixture anddelivering the fuel mixture to the injector pump of the engine, wherebyhomogeneity of the fuel mixture is substantially maintained prior toinjection; an accumulator within the circulation line, whereby pressureand fuel requirement surges are substantially absorbed by theaccumulator; and a feedback line leading from a side of the accumulatorsubstantially opposite the circulation line back to a high-pressurepositive displacement pump, whereby blow by fuel mixture is reclaimedand returned to the positive displacement pump for further processing.6. A system for multi-fuel injection with an engine from at least twofuel supplies, the engine having an injector including an injector pump,the improvement comprising: a manifold in fluid communication with anddownstream of the at least two fuel supplies wherein fuels from the atleast two fuel supplies are mixed to produce a fuel mixture ascontrolled by a combination flow sensor and a control valve locatedin-line between each fuel supply and the manifold; a high-pressurepositive displacement pump in fluid communication with and downstream ofthe manifold and in-line between the manifold and the engine, wherebythe fuel mixture is brought to higher pressure before being injected bythe injector; and a circulation loop connected between the positivedisplacement pump and the injector pump of the engine, the circulationloop including a circulation line and a circulation pump substantiallyconstantly circulating the fuel mixture and delivering the fuel mixtureto an inlet of the injector pump, whereby homogeneity of the fuelmixture is substantially maintained downstream of the positivedisplacement pump.
 7. A multi-fuel co-injection system comprising: apositive displacement pump configured to pressurize a fuel mixture, thefuel mixture comprising a liquid first fuel and a gaseous second fuel;and a circulation line defining a loop in fluid communication with thepositive displacement pump and configured to circulate the fuel mixtureas pressurized by the positive displacement pump.
 8. The system of claim7, further comprising: a first tube for flowing the first fuel; a secondtube for flowing the second fuel; and a manifold in fluid communicationwith the first and second tubes and configured for combining the firstand second fuels to produce the fuel mixture.
 9. The system of claim 8,further comprising a third tube for flowing a third fuel, the third tubebeing in fluid communication with the manifold.
 10. The system of claim9, further comprising a fourth tube for flowing a fourth fuel, thefourth tube being in fluid communication with the manifold, the thirdand fourth fuels being different from each other and from the first andsecond fuels.
 11. The system of claim 7, wherein the first fuel isselected from the group consisting of diesel, bio-diesel, motor oil, andvegetable oil and the second fuel is selected from the group consistingof hydrogen, oxygen, hydrox, propane, natural gas and methane.
 12. Thesystem of claim 7, wherein the second fuel is sourced from a hydrogengenerator.
 13. The system of claim 7, further comprising an accumulatorin fluid communication with the circulation line and configured tostabilize fuel requirement surges within the system.
 14. The system ofclaim 7, wherein: the accumulator is coupled to the circulation line;and a feedback line is coupled from a side of the accumulatorsubstantially opposite the circulation line back to the positivedisplacement pump, whereby blow by fuel mixture is reclaimed andreturned to the positive displacement pump for further processing. 15.The system of claim 7, further comprising a control system wherein: afirst control valve is in fluid communication with the first tube; asecond control valve is in fluid communication with the second tube; anda microprocessor control unit is electrically connected to the first andsecond control valves so as to control the supply of the first andsecond fuels to the manifold.
 16. The system of claim 15, wherein: afirst flow sensor is associated with the first control valve so as toalso be in fluid communication with the first tube and so define a firstcombination sensor and control valve; a second flow sensor is associatedwith the second control valve so as to also be in fluid communicationwith the second tube and so define a second combination sensor andcontrol valve; and the microprocessor control unit is electricallyconnected to the first and second flow sensors so as to account for theflow of the first and second fuels in the first and second tubes asprovided by the first and second flow sensors in thereby controlling thefirst and second control valves and thus the supply of the first andsecond fuels to the manifold.
 17. The system of claim 7, furthercomprising a control system wherein: a combination flow sensor andcontrol valve is in fluid communication with the positive displacementpump; and a microprocessor control unit is electrically connected to thecombination flow sensor and control valve and to the positivedisplacement pump so as to regulate and maintain the pressurization ofthe fuel mixture by the positive displacement pump.
 18. A method formulti-fuel injection comprising the steps of: repressurizing a fuelmixture comprised of a liquid first fuel and a gaseous second fuel;circulating the pressurized fuel mixture; and delivering thepressurized, circulated fuel mixture to an injector pump of an engine.19. The method of claim 18, further comprising the step of supplying thesecond fuel from a hydrogen generator.
 20. The method of claim 18,further comprising the steps of: supplying the first and second fuelsfrom respective first and second fuel sources; detecting the flow of thefirst and second fuels; and controlling the flow of the first and secondfuels using control valves under the control of a microprocessor controlunit electrically connected to the control valves.
 21. The method ofclaim 18, wherein the step of pressurizing the fuel mixture comprisesthe further steps of: detecting the flow of fuel mixture through thepositive displacement pump using a flow sensor; and regulating thepositive displacement pump using a microprocessor control unitelectrically connected to the flow sensor and to the positivedisplacement pump so as to maintain the pressurization of the fuelmixture by the positive displacement pump.